For the purpose of environmental protection, economical running (Eco-Run) vehicles and hybrid vehicles have lately been put to practical use, which automatically suspend the engine while stopping and waiting for the stop signal to change (i.e., while the engine power is unnecessary).
In the air-conditioning apparatus for vehicles, the compressor in the refrigerating cycle is driven by engine power of the vehicle. Therefore, every time the engine of the hybrid vehicle or the like stops at a red light, for example, the compressor is also stopped to increase the temperature of the heat exchanger for cooling (i.e., the evaporator). This will consequently increase the temperature of air blown into the vehicle cabin, which unfavorably produces the problem of impairing cool feeling of the people in the cabin.
JP 2002-337537 A proposes a cold-storage type air-conditioning apparatus for vehicles, which is equipped with a cold storage unit capable of storing cold energy while the compressor is operating, thereby making it possible to cool the air blown from the cooler into the vehicle cabin even when the compressor is stopped (i.e., when the operation of the heat exchanger for cooling is stopped).
It is also known from JP (Hei) 06-234967 A, JP 2003-80933 A, JP 2006-321949 A and JP 2011-51393 A that the cold storage agent for cold-storage type aid-conditioning apparatus employs normal paraffin that can exhibit stable melting and solidification behaviors for an extended period of time and large latent heat.